DAY 1:

Cashew Meringue Wafers:

Separate 10 eggs into egg whites and egg yolks. Let the 10 egg whites come to room temperature. Save the 10 egg yolks for another dish.

Place 2 oven racks on the lower and upper third positions in the oven. Preheat the oven to 350 degrees F. Put 2 cups of cashews in a sheet pan, and toast cashews in the upper third rack of the oven for 15 minutes, until they are golden brown. Set aside and let them cool.

Turn down the oven to 225 F (105 C). Line two large sheet pans (13x18 each pan) with parchment paper. Using a sharpie, draw two 8" x 8" squares on the parchment paper so that there are 2 squares per pan. I draw the squares using the outside of the bottom of a square dish. There should be 4 squares total. Flip the parchment paper over so the side with the sharpie marks faces down, and away from the meringue wafers.

In a food processor, add in the 2 cups of the toasted cashews, 1/3 cup powdered sugar, and 1/4 cup of cornstarch. Pulse till they are mixed and the cashews are very fine - looks like a powder.

In the bowl of your stand mixer, add in the 10 room temperature egg whites. With the whisk attachment, beat on medium speed till the egg whites become frothy. Then increase to medium-high speed, add in the 1 tsp of cream of tartar, and mix it in. Then very slowly add in 1/2 cup of granulated sugar, a little at a time. When all the sugar has been added, increase the speed to high. Continue beating till you see very stiff peaks.

Carefully fold in the cashew powder mixture into the meringue, one third at a time, as well as 1 tsp of vanilla extract, just until it is evenly mixed. Dab a little meringue on the corners of the parchment paper so that it doesn't move around or flap up during baking.

Transfer the meringue mixture into a pastry bag fitted with no metal tip. Follow the traced squares on the prepared parchment paper lined baking sheets to pipe four 8" x 8" squares. Start at the outer edge of each of the 4 squares. Then make a smaller square within each of the 4 squares, and keep going till you fill all 4 squares. If you have excess meringue when you're finished with the squares, that's okay. Just evenly divide the meringue by eye, so that the 4 squares have approximately the same amount of meringue mixture in them. Once all the batter has been piped, use an offset spatula or the back of a spoon to smoothen and flatten the tops of the wafers as much as possible.

Place on sheet pan on the upper third rack and the other on the lower third rack. Bake it in the preheated oven at 225 F (105 C) for 5 hours. Then turn off the oven heat but do not open the oven door. Leave the wafers in the turned-off oven overnight, for the wafers to continue drying out.

The low temperature (225 F) and long baking time (6 hours + residual oven heat overnight) is needed to remove all the moisture from the egg whites and create a hollow and dry wafer, without burning the outer layer of the meringue.

When the wafers are completely dry, they should sound hollow when you tap them. And they should come off the parchment paper quite easily. You can leave them at room temperature uncovered if you're not assembling the cake immediately. This will allow them to dry out more (which is preferred).

DAY 2:

Mango Filling / Topping:

Take 3 fresh ripe mangoes, and slice them so you get 6 halves and 3 seed pieces.

Take 4 (out of 6) halves, and use a big spoon to scoop out the mango flesh, keeping the piece intact. Do this for all 4 halves. With a sharp knife, slice the 4 mango halves cross-sectionally, so you end up with slices of mango that are about 1/4" thick. Save these for the cake topping.

Take the remaining 2 halves and 3 seed pieces. Cut them into small squares using the criss-cross method. Set these aside for the filling in between the meringue layers.

Whipped Cream Frosting:

In the bowl of your stand mixer, add in 8 oz cream cheese. With the paddle attachment, beat on medium-high speed till it's slightly softened. Turn the mixture down to low speed, and add 5 cups of very cold heavy cream, and continue beating for another 1 to 2 minutes till the heavy cream and cream cheese are well incorporated. Stop the mixer and scrape down the bowl and paddle attachment. Add in 1 cup powdered sugar, 2 tbsp cornstarch, 2 tsp vanilla extract, and 1 tsp of orange zest.

Switch to the whisk attachment, and slowly increase the speed as the whipped cream thickens up. If you start at a fast speed immediately, the heavy cream may spill over the edges. Continue whipping like this, slowly increasing the mixing speed, until the cream forms stiff peaks.

Separate about 3 cups of this frosting, add in the small mango squares, and gently fold them in. This will be the filling mixture in between the meringue layers.

Leave the remaining frosting in the fridge till you're ready to use it.

Assembling the Cake:

Take a large flat serving board that's greater than 10" in length. We like to use a 12" board. Dab a dollop of the frosting in the center of the cake board, so that cake doesn't slide around.

Place the first meringue wafer in the middle of the cake board. Then spread one-third of the mango-cream mixture on top.

Place the 2nd meringue wafer on top, and repeat the steps, then adding one-third of the mango-cream mixture. Repeat this with the 3rd meringue wafer and then the last one-third of the mango-cream mixture.

Add the 4th meringue wafer as the final wafer layer. Then frost the sides and the top of this cake with the whipped cream frosting. Smoothen it out with an offset spatula. It's okay if you see some mango or cashew meringue through the whipped cream. This is just to ensure that we have a smooth base surface onto which we can pipe frosting on later (be sure to save some of the frosting for the side decorations).

Add the thinly sliced mango pieces (prepared earlier) onto the top of the cake. I'm arranging them so that they form neat rows of mango slices that slightly overlap with each other. Place the cake in the freezer to let the first base layer of frosting firm up, for about 20 minutes. Store the remaining whipped cream frosting in the fridge.

When the base layer of frosting has firmed up in the freezer for 20 minutes, transfer the remaining whipped cream frosting into a piping bag fitted with a large star tip (I use a 1M tip).

Take the cake out of the freezer, and pipe frosting along the side of the cake starting at the bottom and going straight up, ending right at the top edge of the cake, and create a little flourish by just pulling the tip up at the end.

Repeat this until you've piped these vertical walls of frosting around the entire cake. Try to keep the strips of frosting as close to each other as possible, so it looks like a continuous wall with evenly spaced ridges.

Store the cake in the freezer till you're ready to serve. Let the cake defrost at room temperature for about 20-30 minutes before serving. The cake is meant to be served semi-frozen. Enjoy!